Dreaming of Blueberries

Author: Hannah Zwartz

Article originally published by: Kiwi Gardener

Hannah Zwartz is pleased to see the once elusive blueberry become a nationwide favourite.

When we were kids, blueberries were an Americanism known only in books. Does anyone else remember Blueberries for Sal, the children’s book in which Sal and her mother meet a baby and mother bear while out picking on Blueberry Hill? I can’t remember at what age I ate my first real, fresh blueberry, but now it seems they are everywhere, hailed as a superfood, packed with antioxidant goodness.

Blueberries are quite particular about their growing conditions, but get those right and they can do well across the country. I’ve seen productive bushes, the size of trees, towering overhead and laden with berries. Part of the trick is choosing the right variety, and this depends on the part of the country you are in. Some are deciduous and need winter chilling, while others do well in warmer areas. Most varieties also do best with a different sort nearby to cross-pollinate them.

In their native habitat, blueberries apparently like to grow on riverbanks and on islands in peat bogs, where they get plenty of sun and constant access to water, without being actually waterlogged. If you don’t happen to have a peat bog with an island in your backyard, try to keep the soil moist, but not soggy. This is tricky where I live, on a sand dune, which is probably why I haven’t had much luck with producing great crops. If you are gardening on sand or clay, the best bet might be to grow blueberry plants in a large tub or barrel filled with compost-rich, acidic soil and mulched with woodchip. Blueberry plants are shallow-rooted, so mulch helps protect the roots from drying out. As with all container growing, it’s important to keep the tub well-watered, especially over summer.

As well as lovely fruits, blueberry plants have nice white flowers (drooping bell-like waxy flowers showing their membership of the Ericaceae or heather family). The foliage is attractive, too, sometimes glaucous (with a bluish tinge) and colouring nicely in autumn. So they don’t have to be tucked away in a berry patch, but can feature in a tub on a patio, or even as a low hedge.

Care and pruning

Blueberries don’t need a lot of feeding; compost and mulch will generally supply their needs. Apply compost every year and mulch well to keep the soil damp and reduce weed competition. They need acid soil, so don’t add any lime or wood ash.

Blueberries also don’t need fiddly pruning; most bear berries on second-year wood, so the only pruning needed is to cut out some of the oldest, twiggy growth to encourage new branches to sprout. Remove any crossing branches and any dead, diseased, weak or damages stems, and any that are touching the ground. On older bushes, remove maybe a third of the oldest branches at their base. Prune at any time over winter – ideally in late winter when you will be able to identify the fatter buds, which will produce flowers and fruit, from the thinner leaf buds. Don’t prune the fat buds.

Ripe blueberries develop a silvery bloom.
Pretty bell-like flowers and attractive foliage make blueberry bushes great for tubs or hedges.

Types of blueberry

This can get a little confusing because blueberries originate in the opposite hemisphere, so northern-types are actually suited to our southern areas, and the southern-types, bred for warmer climates, suit northern parts of New Zealand better.

Rabbiteye (Vaccinium virgatum syn. V. ashei)

Suitable for warmer areas, these come from the southeastern United States. They are named because the unripe berries are pinkishwhite, like the eyes of a white rabbit. Rabbiteye bushes are earlyflowering, but fruit later than highbush-types, with different cultivars fruiting from January through until mid-April. They are generally more vigorous and longer-lived than highbush plants, and heavier cropping, but the fruits, while sweeter, are often smaller, with thicker skins. Rabbiteyes crop best with a pollinator of a different type.

Northern Highbush (V. corymbosum)

From the northeastern US and Canada, these are deciduous and need winter chilling to bear fruit (anywhere south of Waikato is said to be OK). It can fruit from mid-November through until February and is suitable for districts from Waikato south.

Southern Highbush

These are crosses developed from V. darrowii, an evergreen bush growing wild in pine forests in the southern US, so they can handle warmer climates. It is best suited for Waikato and northwards. They will need a pollinator (another plant of a different cultivar). Cultivars include: ‘Marimba’; ‘O’Neal’; ‘Island Blue’; ‘Summer Blue’; ‘Misty’.